Which Mac setup would be any good for blender?
A Mac might not be an ideal choice to work with Blender at the moment. The hardware configurations are limiting (GPUs available with Macs are far from optimal for rendering), price/value ratio tends to be very much not to your advantage as well when we start looking at the specs that would be better suited for rendering and similar alternatives. OpenGL technology that Blender relies on entirely was recently deprecated in the OS as well making it a questionable choice for any developers thinking about the future of Blender so the support for the platform might not be as good and might not be improving any time soon. You should carefully consider if it is in your best interest to choose a Mac at all if you need it primarily for 3d work and especially if you are planning to use mostly Blender.